The present invention relates to a socket for electrical parts for detachably holding electrical parts such as semiconductor device (called xe2x80x9cIC packagexe2x80x9d hereinlater), and more particularly, to a socket for electrical parts provided, to be openable, with an open/close member for holding the electrical part.
Conventionally, there is known, as such xe2x80x9csocket for electrical partsxe2x80x9d, an IC socket for detachably holding an IC package as an xe2x80x9celectrical partxe2x80x9d.
This IC socket has a socket body to which the IC package is mounted and to which contact pins contacting terminals of the IC package are arranged. An operation member is further disposed to be vertically movable with respect to the socket body, and through the vertical movement of the operation member, the contact pins are contacted to or separated from the terminals of the IC package. Simultaneously, an open/close member disposed to the socket body to be rotatable or pivotal is opened or closed, and a heat sink provided for this open/close member is contacted to or separated from an upper surface of the IC package.
However, in the IC socket having such structure as mentioned above, when the open/close member pivotally provided for the socket body is closed, the heat sink abuts against a tip portion of the IC package. Accordingly, as the number of the insertion-withdrawal of the IC package is increased per unit time, the opening or closing speed of the open/close member must be made fast, and at a time when the closing speed is fast, the heat sink of the open/close member will abut against the tip portion of the IC package with a large impact force, thus providing a problem.
An object of the present invention is to eliminate problems encountered in the prior art mentioned above and to provide a socket for electrical parts capable of reducing an impact to the electrical part by reducing a closing speed of an open/close member disposed to a socket body.
This and other objects can be achieved according to the present invention by providing a socket for an electrical part comprising:
a socket body to which an electrical part having terminals are mounted;
a number of contact pins arranged to the socket body so as to be contacted to or separated from the terminals of the electrical part;
an operation member mounted to the socket body to be reciprocally movable with respect to the socket body;
an open/close unit mounted to the socket body to be opened or closed in accordance with the reciprocal motion of the operation member and to press the electrical part when closed; and
a reduction means arranged for the open/close unit so as to reduce a closing speed thereof when the open/close unit is rotated in a closing direction thereof.
In preferred embodiments, the electrical part is an IC package having a tip portion and the open/close unit is provided with a heat sink unit for diffusing a heat of the tip portion of the IC package through the contact thereto.
The closing speed reduction means is composed of a point of force portion formed to the open/close unit to be pressed by the operation member, first and second fulcrums formed thereto as pivotal fulcrums of the open/close unit, and a point of action formed thereof so as to press the electrical part, a distance between the second fulcrum and the point of action is smaller than a distance between the first fulcrum and the point of action, and when the open/close unit is closed form the opened state, the pivotal fulcrum is transferred from the first fulcrum to the second fulcrum to thereby reduce the closing speed of the open/close unit.
The open/close unit includes a pivotal arm having substantially a gate shape, and the first fulcrum is a first pivotal member provided for the socket body, the second fulcrum is a second pivotal member provided for the socket body and the point of force is a force point shaft formed to the pivotal arm.
An urging spring may be further disposed for applying an urging force to a front end portion of the open/close unit in the closing direction thereof.
The open/close unit comprises a pair of open/close members which are opened or closed together in an opposed attitude and the heat sink unit comprises a pair of heat sinks provided for the open/close members, respectively.
The closing speed reduction means may be composed of first and second pivotal projections provided for the pivotal arm as first and pivotal fulcrums and first and second rotation (pivotal motion) support members formed to the socket body, the first rotational projection being fitted to the first rotation support members to be pivotal and the second pivotal projection being fitted to the second rotation support member to be pivotal when the first pivotal fulcrum is transferred to the second pivotal fulcrum in accordance with the closing operation of the open/close unit.
According to the socket for an electrical part of the structures and characters mentioned above, when the open/close unit is rotated in its closing direction, the closing speed can be reduced by the location of the closing speed reduction means, thus reducing an impact force at an abutting time of the open/close unit against the electrical part. Furthermore, since closing speed of the open/close unit can be reduced from the closing intermediate point, the rotating (pivotal) speed of the open/close unit to the closing intermediate point can be set to be relatively fast, so that the total closing time is not so elongated. Thus, in the case of the performance test with the electrical part being mounted to the socket, the insertion-withdrawal number is not so reduced per unit time. Furthermore, this speed reduction means is composed of relatively simple structure, so that the closing speed reduction can be easily performed.
Still furthermore, the tip portion is disposed at the heart portion of the IC package, so that the reduction of impact to this tip portion is significantly effective and advantageous.
Further, since the urging force of the urging means such as spring acts to the front end portion of the open/close unit, the pressing force of the open/close unit to the electrical part is not adversely reduced.
The present invention is effectively applicable as an IC socket for an IC package as electrical part.
The nature and further characteristic features of the present invention will be made more clear from the following descriptions made with reference to the accompanying drawings.